Process of uniting two rubber surfaces



Aug. 24,1926. y 1,597,432 L. B. CONANT v PRocEss'F' UNITING Two .RUBBER SURFAGES Original Filed Sept l0 1920 Figa' ef F. Invenfor,

LeonB. Canam/'Lf amine,

By MM Patented Aug. 124,' 1926.

e UNITED STATES.

1,597,432 PATENT orrlcE.,v

LEON B. conm, or amamos, mssacnusn'r'rs.

PROCESS F `U'NI'IIIEI'G TWO RUBBER SUBFACES.

Application illediepteniber 10, 1920, Serial No. 409,398. Renewed Iar'ch i7, 1926.

This invention has for-.its object the effecting of an improved methodv for molding treads on tires, heel and sole treads for' boots and shoes, and elsewhere in which it is desired to have wear receivingportions capable of being'readily removed, and yet held in placesufliciently secure for all ordinary use. n

. In carrying my process into eiect I intror` duce between/the surfaces to be molded together a membrane or flatly extended ele-` ment adapted ,toprevent the entirev molding together of the twoA surfaces, permitting onlv enough cohesion to give a practically suicient attachment, but not enough to prevent the tread from beingstripped of when desired.

In p specification, Fig. I1 is afperipheral view of a portion of a tire after the neutralizing element has been applied thereto. Fig. 2 is a cross section of a pneumatic tire before the tread has been molded upon it. Fig. 3 is a cross section of the tire after the tread has been moldedjthereon. Fig. 4 is a face viewof another form' of the Lneutralizing element.

Fig. 5 is a face view of a neutralizing ele.

mentada ted for heels. Fig. 6 is a vertical section o a complete heel produced by my 30, process. Fig. 7 is a face view of another neutralizing element.

I- willrst describe the process as applied? to tires composed of rubber, and especially to those known as pneumatic tires. These tires 1 are provided with extra thicknesses of rubber about their peripheries to form a wear resisting tread 2, usually composed of solid rubber, whereas thev tire itself is built up of rubber and fabric., the whole beingl 0 solidly vulcanized together. E v y To enable such treads to be removed from the tire when worn, for the substitution of a freshv one, without the aid of machinery, without injury to the tire, and by hand alone, introduce between the tread and tire any one of several dierent ,forms of neutralizer. `Thatillustrated in Figs-1, 2'and 3 ,consists of several thin narrow strips 3 preferably composed of libre board. In applying them 5 to the periphery of the tread 1, they are first 4 processed in contact with some form of ady esi've material, but preferably rubber composltion, in order that they shall remain jin place upon the tire during the remainder o the process. EachA strip 3 preferably passes A tire 1 and the neutralizing element 3; put lnto a mold and vulcanized-together in f `the usual manner. Wherever rubber meets the drawings formingpart of this I ytween tread and carcass.

upon the carcass 1but this is not essential.

e in the form of strips 3, because giving more.

entirely about the periphery of the tire, being cut to have its ends come somewhat close together.

Then the treadl 2 is put in place upon the rubber along the juncture ofvv the tread and tire, the same will be made to unite as one,

but where the strips 3 intervene there will be no such cohesion. Hence by limiting the spaces-between the strips 3 relative to the widths of the latter, the cohesion of tread and tire can be reduced to any desired extent, until a comparatively small exertion of muscular strength will suiiice to separate the tread from the tire.

While, on many accounts, I prefer .the strips 3 as a neutralizin element, a single thin sheet4 maybe use for thus se arating'the tread from the carcass 1, but i composed of fibre board or the like, it should be provided with a suicient number of perforations 5 to give the required cohesion be- This sheet is illustrated in Fig. 4.

As shown in Fig, 7, the-neutralizer may consist of an unslotted, imperforate sheet 7 4which will serve the purposeof giving a separable juncture between the tread and .85. the balance of the tire. This element 7 as` well as the neutralizer strips 3 andthe perforated sheet 4, may be glven a coating ofl rubber composition' prior to application While the imperforate neutralizer 1 will serve the purpose ofv holding the tread 2 in` 1pllace durlng all ordinar use, I- prefer to ave the neutralizer eit'er perforated -or positive resultsfor all kinds of conditions. of use-and abuse.

Similarly, the wear resisting member or tread 10V is a plied to the balance 11 of a heel, a thin s eet 12 suitably perforated, as 100 at 13, b'eingimolded between the members 10, 11.- As shown in Fi 5, the neutralizer. element 12 has practica ly all its perforations nearV its edge, but this is not essential.

When the rubber members 10 and 11 are 106 I thus molded together,- with the neutralizer 12 between, the tread 10 can at any timebe Y forcibly stripped oif fromthe heel portion f 11, and a new tread ap lied. The advang' tage o f this is that it enafles the shoe manu? facturers to ship the heels complete, while at the same time permitting the shoes to be easily re-heeled at any time.

While this present application covers the process of forming articles with removable wear-resisting parts, my companion application iled July 1, 1920, Serial No. 393,459, is designed to cover the structure, particularly as applied to heels and treads of boots and shoes. An even more perfect form of thesole and heel in which this process is employed is set forth in another companion application filed July 12, 1920, Serial No. 395,752.

Although I have described thinfibre board as best adapted for use as a neutralizer, I

also design to use a fabric, such as tire-duck;

' take olf all the remaining neutralizer before applying the new shoe. This new shoe or tread is preferably made with a gum-coated1 fresh neutralizer built in its inner periphery, so that the combined tread and neutralizer can be applied as one andV in a well known manner. It is obvious that this facilitates retreading, in that the new shoe and the neutralizer are applied as a unit, but I do not restrict myself to this system, as the neutralizer may be'applied directly upon the old carcass in the same mannel` as above described for a new one.

It should be noted that a sheet of fibreboard introduced 1between the shoe and carcass as aneutralizer, or introduced within the carcass itself, will serve. most effectively to prevent puncture of the inner tube.`

lVhat I claim is: n

1. The herein described process of detachably uniting two rubber surfaces, which consist in vulcanizing one rubber surface to the other at numerous closely disposed areas separated by numerous closely disposed areas incapable of cohesion, whereby the surfaces can at will be stripped from each other.

2. The herein described process of detachably uniting two rubber surfaces, which consists in vulcanizing one rubber surface to the other in parallel lines separated by parallel lines incapable of cohesion.

3. The herein described process of v detachably uniting two rubber surfaces, which consists in applying a number of narrow strips relatively close together upon one surface and vulcanizing the other surface thereto, so that said surfaces adhere to each other solely between the strips at a plurality of narrow areas, and are therefore readily detachable from each other.

In testimony that I claim the fore oing invention, I have hereunto set lmy han this 9th day of September, 1920.

. LEON B. CONANT. 

